Network


Latest external collaboration on country level. Dive into details by clicking on the dots.

Hotspot


Dive into the research topics where N. R. A. Bird is active.

Publication


Featured researches published by N. R. A. Bird.


Plant and Soil | 2011

Estimating soil strength in the rooting zone of wheat

Andrew P. Whitmore; W. Richard Whalley; N. R. A. Bird; C. W. Watts; Andrew S. Gregory

When roots abstract water thus drying the soil, crop growth may be reduced by increasing strength of soil as well as the lack of water. Strong soil impedes root growth, restricting access to deeper water. As a result, there is a need to estimate soil strength in order to model crop response to dry soil correctly. The strength of soil can be routinely assessed with a penetrometer but measurements are time consuming and hard work to acquire at the frequency required to understand soil-water-plant relations. To make progress, a published relationship that derives penetrometer pressure from both water relations in soil and density was improved to take account of the effects of depth including the friction that results from the increasing hydrostatic pressure. These relationships were then incorporated into an agroecosystem model so that the dynamics of strong soil and its effect on wheat could be simulated. The combined model requires the moisture release curve (but this can be derived from other commonly-measured soil properties), daily rainfall, temperature, and potential evaporation and the agronomy of the crop. Modelled values of penetrometer pressure were simulated well compared with measured values in artificially strengthened (compacted) and weakened (irrigated) soils. Simulations of the strength of soil and the matric potential before anthesis are compared with measured total dry-matter yields of winter wheat in experimental fields. The results lend weight to the hypothesis that wheat yield is limited by the strength of soil in the field and that soil strength, rather than soil matric potential, better explains differences between soils.


Soil Biology & Biochemistry | 2008

Mineralization of native soil organic matter is not regulated by the size, activity or composition of the soil microbial biomass—a new perspective

Sarah Kemmitt; Clare Lanyon; Ian Waite; Q. Wen; Thomas Addiscott; N. R. A. Bird; Anthony G. O'Donnell; P.C. Brookes


Soil & Tillage Research | 2006

Calculation of the compression index and precompression stress from soil compression test data

Andrew S. Gregory; W. R. Whalley; C. W. Watts; N. R. A. Bird; Paul D. Hallett; Andrew P. Whitmore


European Journal of Soil Science | 2005

Structural differences between bulk and rhizosphere soil

W. R. Whalley; B. Riseley; P. B. Leeds-Harrison; N. R. A. Bird; P. K. Leech; W. P. Adderley


European Journal of Soil Science | 2005

Measurement of the size distribution of water‐filled pores at different matric potentials by stray field nuclear magnetic resonance

N. R. A. Bird; A. R. Preston; Edward W. Randall; W. R. Whalley; Andrew P. Whitmore


Water Resources Research | 2010

Measurement and simulation of the effect of compaction on the pore structure and saturated hydraulic conductivity of grassland and arable soil

G.P. Matthews; Giuliano M. Laudone; Andrew S. Gregory; N. R. A. Bird; A. G. de G. Matthews; W. R. Whalley


Soil Science Society of America Journal | 2010

Deformation and Shrinkage Effects on the Soil Water Release Characteristic

Andrew S. Gregory; N. R. A. Bird; W. Richard Whalley; G. Peter Matthews; Iain M. Young


Soil Use and Management | 2006

Quantification of the effects of contrasting crops in the development of soil structure : an organic conversion

Apostolos Papadopoulos; Sacha J. Mooney; N. R. A. Bird


Journal of Hydrology | 2011

A model to predict the effects of soil structure on denitrification and N2O emission

Giuliano M. Laudone; G.P. Matthews; N. R. A. Bird; W. R. Whalley; Laura Cardenas; Andrew S. Gregory


European Journal of Soil Science | 2001

The design of porous material sensors to measure the matric potential of water in soil

W. R. Whalley; C. W. Watts; M. A. Hilhorst; N. R. A. Bird; J. Balendonck; D.J. Longstaff

Collaboration


Dive into the N. R. A. Bird's collaboration.

Top Co-Authors

Avatar
Top Co-Authors

Avatar
Top Co-Authors

Avatar
Top Co-Authors

Avatar
Top Co-Authors

Avatar
Top Co-Authors

Avatar
Top Co-Authors

Avatar
Top Co-Authors

Avatar
Top Co-Authors

Avatar
Top Co-Authors

Avatar
Researchain Logo
Decentralizing Knowledge